Spark-control mechanism for internal-combustion engines



\ May 22, 1928.

' 1,670,803 c. E. FURGASON SPARK CONT ROL MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed Dec. 15, 1926 2 Sheets-Sheet l anvzuto'v (2a v eflfraasdzz H3 MW attonwqo May 22, 1928. I

. C. E. FURGASON SPARK CONTROL MECHANISM FOR INTERNAL COMBUSTION ENGINES Filed Dec. 15, 1926 2 Sheets-Sheet 1'2 Patented May 22, 1928.

, umrsu STATES PATENT OFFICE.

CLAUDE E. FUBGASON, OF LANSING, MICHIGAN, ASSIGNOB TO BEO MOTOR CAB COI- I'ANY, OF LANSING, MICHIGAN, A CORPORATION OF MICHIGAN.

SI'ARK-CONTBOL MECHANISM FOR INTERNAL-COMBUSTION ENGINES.

Application filed December 18, 1826. Serial No. 154,828.

This invention relates to spark control mechanism for internal combustion engines and more particularly to a spark control mechanism which automatically adjusts the spark to obtain correct. ignition at all speeds of the motor and under the varying conditions of load upon the engine.

This invention relates to the type of apparatus described and claimed in my copending application, Serial No. 96,904 filed March 23, 1926 but contemplates certain improvements in this prior construction tending to simplify the structure, render the same more compactv and thus cheapen,the Eost of manufacture and facilitate the assem- Automatic control of the timing of the igiiition for internal combustion engines has recently been adopted more or less universally by the manufacturers of motor vehicles but irr most instances such so called automatic spark control mechanisms have not proven to be fully automatic as they do not provide for a correction of the time of ignition according to all conditions of motor operation. As a cbnsequen'ce the majority of the alleged full automatic spark controlling mechanismsdlave proven ineflicient in actual practice. Asa result of this many motor vehicle manufacturers are equipping their motors with the so-called semi-automatic ignition controlling'means as a compromise between the old manual control spark and the full automatic spark control. With the semi-automatic spark control the spark is controlled by meansof a governor operated in accordance with the speed of the motor whereby as the speed increases the spark is advanced. Under ordinary circumstances this governor control would act satisfactorily if the load conditions imposed '1 upon the motor were at all times uniform.

However, inasmuch as they are not the semiautomatic control provides for a further adjustment or correction of the time of igni--. tion by a manual control lever whereby the spark may be retarded .when the motor is operating under a heavy load. It is also the practice to retard the spark by this manual control when the motor is started. The skill necessary in order to properly manipulate the manual control lever to properly retard the spark upon an increase .in load renders the operation of these semi-automatic spark controls erratic and unsatisfactory as the operatpr usually either improperly adjusts the manual control lever or fails to operate the same at all.

As a consequence a full automatic spark control, to be efficient and practical in actual. use must provide means, additional to the speed governor control, for additionally ad justing the spark or correcting the same in accordance with load or other conditions and this latter means must be fully automatic and out of the control of the operator.

The governor controlled mechanism for all practical purposes must be so adjusted that it will, under light loads or usual conditions of the motor, cause a relative high advance of the spark. This means that the spark must be originally set slightly ad- Vanced in order that the governor may produce the desired hi h advance of the spark. It has furthermore een found to be impractical in actual practice to cause the governor to take control of the spark before a speed of approximatel ten miles per hour has been attained. herefore, at-the outset no automatic control is provided for the spark and furthermore the position of the spark is too far advanced to facilitate the safe and easy starting of the motor. With the semiautomatic control the difliculty of the advanced setting of the spark is overcome in starting by retardin the spark by the manual control lever an as the engine is started this lever is returned toits original position and the spark is then wholly under the control of the overnor. Obviously while such an advance spark is eflicient under idling or light loads the sudden loading of the motor and the consequential increase in the supply of fuel thereto will result in a knocking or piriging which is harmful. On the other hand if the spark is originally set lower so that increases in load upon the motor will not result in the disadvantages just mentioned then the highest efliciency under light load conditions is not obtained.

The efliciency of motors equipped with either semi-automatic. or full automatic spark control mechanisms is oifttimes effected by the sluggishness or lack of pickup owing to the inadequacy of the-speed control device to quickly advance the spark at the outset. Thus a full automatic spark control mechanism must contemplate means for initially imparting a rapid advance tothe spark to thus cause a rapid pick-up from crease in the amount of fuel fed to the engine cylinders is in direct proportion to the increase of" the load upon the motor the means for correcting the spark aforesaid may conveniently be operated by or simultime of ignition is positively and automati taneously with the fuel throttle.

This invention has therefore as its object to provide means associated with the usual governor control for the spark whereby the cally additionally adjusted to correct the spark in accordance with conditions to which the governor controlled mechanism is not responsiveand to thus provide a spark control mechanism which both theoretically and in actual practice is fully automatic. Another object ofthe invention is to provide a construction capable of accomplishing the above objects which is simple, compact and which may be manufactured, assembled and operated with facility.

The details of construction of an embodiment' of this invention, as well as the ob jects, and'advantag'es ofthe invention will be made more apparent as this description proceeds, especially when considered in conncction with the accompanying drawings wherein;

Figure 1 is a fragmentary side elevational view of a generator and a spark timing mechanism with my invention applied thereto.

tional view through the timing mechanism and the distributor head.

Figure 4 is a topplan view of the timing mechanism with moved.

the distributorhead -re- Figure 5 is a horizontal sectional view taken substantially on-the plane indicated as by line 5-5 in Fi ure 1 and Figures 6 and are fragmentary elevatlonal views showing the adjusting mechanism in different positions.

Referring now particularly to the drawings wherein like reference characters indi-- cate like parts it will be noted there is fragmentarily illustrated a generator 10, the

shaft 11 of which is connected by means of a gear 12 to the drive shaft 13. of the spark timingmechanism through the intermediary of a pinion 14. Shaft 13 extends up through casing 15 and is connected through a centrifugal mechanism indicated generally by the reference character 16 to a timer shaft 17 carrying timer cam 18. While the details of the centrifugal mechanism are immaterial its function is obvious it being a well known means of advancing the timer shaft 17 relative to the driving shaft 13 as the speed of the engine increases. As viewed in Figure 4 the advance of the spark is effected by moving timer shaft 17 and consequently cam 18 in a clock-wise manner.

Cam 18 is adapted to be rotated in a clock-wise direction for oscillating timer lever 19. which is pivota lly supported as at 1 20 to the shell 21. The shell 21 is rotatably mounted on the casing 15 by means of a tu bular portion- 22 which extends. therein. With the timer lever 19 mounted upon the shell '21 it will be obvious that a rotation of this shell will also effect the timing of the ignition as the timer lever will be. moved relative to cam 18.

Encircling the tubular extension 22 of shell 21 is a collar 23 in the form of a split ring the ends of which are united by a bolt or set screw 24 whereby the same may be assembled and clamped into engagement with this tubular extension 22. The collar 23 is provided with a substantially horizontally extending arm 25 having a graduated segmental portion 26, the graduations of which cooperate with a fixed mark on the shell so that the collar may be rotatively adjusted relative .to the shell and the extent or position of the adjustment indicated by the or abutment 27 which may be recessed on 'one side thereof to provide a bracket or seat for a spring 28 which bears withits other e nd against an abutment 29 projecting from casing 15. The purpose of spring'28 is to normally urge shell 21 toward the left as seen in Figure 1.'

Pivotally mounted on the casing 15 as at 30 is a lever 31. This lever is provided with an extension or lip 32 which engages extension 27 on collar 23 on the side thereof opposed to springv 28. The purpose of this lever is to cause a rotation of shell 21. Piv

oted as at 33 is an operating lever 34ada-pted to be operated by or simultaneously with the fuel throttle of the engine. For this purpose this lever may be connected by means of a link 35 to a throttle control lever 36 mounted on throttle control rod 37. The reference character 38 indicates a throttle pedal lever and 39 the throttle pedal. As the throttle pedal 39 is depressed lever 34 will be swung to the right as viewed in Figure 1.

The lever 34 carries a roller 40 which-is adapted to engage the adjacent edge of lever the'positions to which the lever 31 is adjusted by reason of the engagement of the roller 40 of lever 34with this cam surface. As shown in Figure 1 the roller 40 in one of the extreme positions of the levers reposes in recess 41 and for the purpose of preventing accidental disengagement of the roller with the cam surface the end of lever 31 may be extended to form a hook-shaped stop 42. Y During the first movement of lever 34.to the right, roller 40 engages the crest of cam 43 and thus moves lever 31 to the right which causes a movement of shell 21 in the direction of arrow A, see Figure 1, or in a counterclock-wise direction which results in a rapid advance of the spark. The roller of cam recess 41 is such that the spark is normally held in a suin'ciently retarded position to permit the ready starting of the motor. This position of the spark is also suitable for the motor under full idling,

no load condition. However, immediately upon. any movement of the lever 34, whic would be the result of any depression of throttle pedal 39, roller 40 starts to move up the side of cam recess 41 to the cam crest 43 and this causes a rapid displacement of lever 31'to the right and as a consequence a rapid advance of the spark. This provides the desired kick-off or initial acceleration of the motor and steps up the position of the spark from the full retarded position suitable for starting to a position where the spark is advanced sufliciently for the highest efliciency of operation. This position of the levers is illustrated in Figure 6 and under light load conditions the levers. will remain more or less in this position. However, as the load upon the motor increases and it becomes necemary to o n the throttle further to supply more fuei to the engine cylinders the lever 34 will be moved further toward. the right toward or into the position illustrated in Figure 7 wherein the roller 40' is in engagement with the cam surface 44 which permits a movement of lever 31 toward the left or in a direction opposite to the movement of lever 34. This -movement of lever 31 permits spring 28 to engine and the load thereon.

move shell 21 toward the left or in a clockwise direction which retards the spark, 1t being readily apparent that the amount the spark is retarded increases simultaneously with and in proportion to the increase; 111 load as determined by the further openlng of the throttle. As pressure upon the throttle pedal 39 is released the lever 34 will return to itsposition illustrated in Figures 6 or 1 and the movements of the lever 31 will be inversely to those just described.

' It will be apparent from the foregoing description that the advantages outlined hereinbefore are obtainable with the herein described construction and that a control mechanism which is fully automatic is produced. It will be understood that the adjustments imparted to the spark timer mechanism are in addition to and independent of the adjustment resulting from the centrifugal device 16. In fact the centrifugal device adjusts thetime of ignition through the cam .18 while the mechanism controlled by the throttle adjusts the timer lever 19.

Obvious changes may be made in the specific construction herein described without departing from the spirit and scope of this invention and to this end reservation is made to make such changes as may come within the purview of the accompanying claims. e

What I claim as my invention is 1. In an internal combustion engine, means for timing the ignition including two movable parts, a speed governor controlling one of said parts and a cam member controlling the other in accordance with theposition of the fuel throttle of the engine to first advance and then retard the same, whereby thetime of ignition is determined by the combined effort of the speed of the 2. The combination with a governor con trolled spark timing mechanism and a throttle for internal combustion engines, of a single control means operable by said throttle and acting to initially impart an advance to said spark timing mechanism and to subsequently retard said mechanism in proportion to the extent said throttle is opened.

3. The combination with a speed governor I controlled spark timing mechanism and a fuel throttle for an internal combustion engine, of means for additionally. adjusting said timing mechanism including a cam member operated by said throttle and de- 1 signed. to initially advance said timing mechanism and subsequently retard the same in proportion to the opening of the throttle. l r

4, The combination with a speed governor controlled spark timing mechanism and a fuel throttle for an internal combustion enlid gine, of means for additionally adjusting said timing mechanism including a cam member operated by said throttle and designed to permit a full retardation, initially advance said timing mechanism and subsequently relatively retard the same in pro-,

portion to the opening of the throttle.

5'. The combination with a spark timing mechanism including a movable part and a throttle for an internal combustion engine, of adjusting mechanism for said timing mechanism comprising, a lever actuated by said throttle and a second lever operated thereby for adjusting said movable part, said second lever being provided with a cam surface engaged by said first lever, said cam surface includinga recess permitting full 6. The combination with a spark timing i mechanism including a'movable part and a throttle for an internal combustion engine, of adjusting mechanism comprising, a lever actuated by said throttle and a second lever operated thereby for adjusting said movable part, said second lever being provided with a cam surface engaged by said first lever and so shaped that a movement of said first lever in one direction effects a movement of said second lever in both directions. i v

In testimony whereof I afiix my signature.

' CLAUDE E. FURGASON. 

